private unsafe void TestIndexOfWorksForAllLocations(ref ReadableBuffer readBuffer, byte emptyValue)
{
byte huntValue = (byte)~emptyValue;
Vector <byte> huntVector = new Vector <byte>(huntValue);
// we're going to fully index the final locations of the buffer, so that we
// can mutate etc in constant time
var addresses = BuildPointerIndex(ref readBuffer);
// check it isn't there to start with
var found = readBuffer.IndexOf(ref huntVector);
Assert.True(found == ReadCursor.NotFound);
// correctness test all values
for (int i = 0; i < readBuffer.Length; i++)
{
*addresses[i] = huntValue;
found = readBuffer.IndexOf(ref huntVector);
*addresses[i] = emptyValue;
Assert.True(found != ReadCursor.NotFound);
var slice = readBuffer.Slice(found);
Assert.True(slice.FirstSpan.UnsafePointer == addresses[i]);
}
}